Zoology and wildlife conservation

Identification of an amino acid-base contact in the GCN4-DNA complex by bromouracil-mediated photocrosslinking

Article Abstract:

The bromouracil-mediated photocrosslinking technique was employed to demonstrate that alanine at position 238 of yeast transcriptional factor GCN4 touches or is near to the thymine 5-methyl of A.T at position +3 of the DNA site in the GCN4-DNA complex. This finding bears out the induced helical fork model for the structure of the GCN4-DNA. The photocrosslinking method used needs no prior data on the complex's genetic structure and should produce reliable generalizations about DNA-binding proteins that affect the DNA major groove.

DNA polymerase-alpha is essential for mating-type switching in fission yeast

Article Abstract:

The switch (swi) gene swi7 of the fission yeast Schizosaccharomyces pombe has been sequenced and assessed for its molecular effects. Swi7 takes part in the yeast's double-stranded chromosomal break (DSB) that triggers recombination during mating-type switching. Furthermore, a gene that complements swi7 maps to chromosome I and encodes the yeast's DNA polymerase-alpha. DSB formation may therefore be associated with DNA replication.